Handheld power tools are well-known. These tools typically include an electric motor having an output shaft that is coupled to a tool mount for holding a tool. The tool may be a sanding disc, a de-burring implement, cutting blade, or the like.
Electrical power is supplied to the electric motor from a power source. The power source may be a battery source such as a Ni-Cad, Lithium Ion, or an alternating current source, such as power from a wall outlet.
The power source is coupled to the electric motor through a power switch. The switch includes input electrical contacts for coupling the switch to the power source and a moveable member for closing the input electrical contacts. The moveable member is biased so that the biasing force returns the moveable member to the position where the input electrical contacts are open when the moveable member is released.
Closure of the input electrical contacts causes electrical current to flow through the motor coils, which causes the motor armature to rotate about the coils. A speed control is usually provided on these power tools to govern the electrical current that flows through the motor.
Typically power tools are designed for one function. Some power tools may provide one or two utilities, such as a power drill used as a power screwdriver. However, generally different power tools are needed for different applications. For example, typically a power sander is not well suited to cut a pipe. In recent years some tool manufactures have provided a pseudo-universal power tool for a variety of applications. Many of these tools operate on the basis of converting rotational movement of the motor to an oscillating motion by a tool mount to which a tool is attached. However, even without the power tool engaging a workpiece, the vibration resulting from the oscillation is annoying and uncomfortable for the user of the tool.
Therefore, a pseudo-universal power tool is need that reduces or eliminates vibration transferred from the tool to the user of the tool.